nix: remove useless inputs, update

Author: RCasatta

flake.lock

@@ -6,14 +6,10 @@
       url = "github:oxalica/rust-overlay";
       inputs = {
         nixpkgs.follows = "nixpkgs";
-        flake-utils.follows = "flake-utils";
       };
     };
     crane = {
       url = "github:ipetkov/crane";
-      inputs = {
-        nixpkgs.follows = "nixpkgs";
-      };
     };
   };
   outputs = { self, nixpkgs, flake-utils, rust-overlay, crane }: